The invention relates to a top shield arrangement for protecting filter traps of cable television systems from tampering by unauthorized persons. More specifically, the invention relates to such an arrangement which includes security means for preventing such tampering and unauthorized removal of the filter from the arrangement.
It is well known that signals of cable television systems are delivered from the central station to the subscribers by cable. The cables are exposed in aerial installations or run along sidewalls of buildings to make their way to the subscribers.
Cable companies may provide a large number of services not all of which would be subscribed to by each subscriber. Thus, in addition to offering local channels, cable companies may also offer pay channels such as movie network, sports network, news network, etc. As all of these services are carried on the same cable, the services which are not paid for by a subscriber must be filtered out in the cable going to the subscriber. For this purpose, filter traps are placed in the line between the main trunk of the cable television system and the television set of the subscriber.
The filter traps are quite often unavoidably disposed in positions in which they can be accessed by unauthorized people. Thus, the filter traps are typically not disposed in the home of the subscriber where they could be easily tampered with by the subscriber. Instead, they are disposed in the out-of-doors environment where they could conceivably be tampered with by unauthorized persons.